Method of refrigeration



B. THOENS.

METHOD OF REFRIGERATION.

APPLICATION FILED MAY 28. I919.

1 ,369,865, Patented Feb. 22, 1921.

ATTORNEYS UNITED STATES BURCHABD THOENS, OF NEW YORK, N. Y.

METHOD OF REFRIGERATION.

Specification of Letters Patent.

Patented Feb. 22 1921.

Application filed May as, 1919. Serial no. 300,307.

To all whom it may concern Be it known that I, BURQHARI) TrionNs, a citizen of the United States, and resldinlg at New York city, New .York county, ew York State, have invented certain new and useful Improvements in Methods of Refr geration, of which the following 1s a speci cation.

This invention relates to improvements in methods of refrigerating and has for its object to provide an improved method combining the advantages of the vacuum-and absorptlon systems of refrlgeratlon, at the same time avoiding the disadvantageous features of these systems.

In the vacuum system a tank is provided having a vacuum. pump associated there with for creating a. vacuum therein. above thesurface of the refrigerant. The vapori zation which takes place at the upper sur-s face of the refrigerant; owing to the low pressure in the tank, cools the remainder of the refrigerant which is circulated through.

aneexternal circuit including an ice box, re- I frigerator,'or other similar cooling device. It has usually been foundthat in addition to the vacuum pump it is necessary to use an acid to absorb the vapors and remove them from the tank to insure rapid vaporization, and also to avoid the use of a. very large vacuum pump.

In the absorption system a liquid 15 used asa refrigerant which is easily dimolved in I water but which has a low vaporization temperature. A generator is provided which contains refrigerant in solution. Heat 1s applied to the generator to. volatilize the refrigerant which passes into a condenser where it is liquefied and from the condenser the refrigerant flows through an expanslon valve, being expanded from a liquid to a gas. In thus expanding, the refrigerant absorbs heat in a well known manner to cool the interior of an ice box, or to do similar work.

After having passed through this external work circuit it flows into an absorber in which is located a-considerable quantity of a weak solution .of the refrigerant.

The refrigerant passing into the absorber is dissolved in this-weak solution making it ening.

In my invention I make use of the prin-" clple of the vacuum system in that I cool a large body of refrigerant by creating a vacuum above it in a. tank and causing it to va orize and then circulate the cooled refrigerant through the external work circuit. Instead of using the ordinary refrigerant, such as water, which is ordinarily 'used in the vacuum system, I use a solution of ammonia or similar liquid, which is easily.

- vaporized, and instead of conducting away and losing. the vapors, as is done in the vacuum system, I provide an absorbing tank in which the vapors are absorbed and the strong solution created thereby returned to the vaporizing tank. The Weak solution of the vaporizin' tank is at the same time constantly trans erred to the absorbing tank to come in contact with and. absorb an addi- In my improved method, which com bines as above explained, the vacuum and the absorption systems, I avoid the use of acids peculiar to vacuum systems and avoid the use of the condenser and expansion valve, also the heat supply ing mechanism of the absorption system. None ofthe various elements of my apparatus are subjected to high pressures such as exist in'the absorption system in the generator, condenser, and piping between the generator and theexpansio'nvalve. There is, therefore, little tendency for the refrigerant to escape from the system. The danger of ex losion is also avoided, as well as decompos tion of the refrigerant itself. '96

The improved method will be fullydisclosed in the following description when taken in connection with the accompanying drawings in which;

Figure 1 is a diagrammatic view of a refrigerating apparatus, for practising the present inventlon; I

Fig. 2 isa similarview of a modified form of the ap ratus. Referring to ig. 1 of the drawings which illustrate a preferred form of a paratus for carrying out the; invention, the referencenumeral: 10 indicates a vaporizing tank taining a body of refrigerant, such tum: I

monia in solution, as indicated, at S, andjthie in tank 11 is an absorbing tank which isabouti 1 one-half full of the solution. lconnecting v end' communicating the tanks and 11 are three separate conduits or pipelines indicated at 12, 13 and 14 in the drawings. The conduit-12 has one with the top of the tank 10 and itsother en opening near the bottom .of the tank 11, and this conduit includes at a point intermediate its ends a vacuum-pump I 15 preferably of the rotary type. The func- 1 commonl tion of the pump 15 is to reduce the pressure and create a partial vacuum in the tank 10 above the surface of the solution, thereby causing art of the refrigerant to vaporize to cool the remainder thereof. Any water which may be vaporized will pass with the refrigerant va rs to the absorber and will be condensed m that vessel; Nov analyzers or rectifiers' are necessary to overcome and' eliminate'the water vapors, such as are now used in modern absorption systems.- T is'is'another point of superior ty of the presentsystem over the absorption "systems heretofore used. The vapors drawn from thetank. 10 are forced by the pump into the tank 11, emerging from'the condult' 12 near the bottom thereof, where they are, absorbed b the solution in this latter tank.

Through t e conduit 13 a warm, strong solution'of the refri rant 1s constantly being withdrawn from t e tank 11 and transferred duit is constantly passing a coo weak so.

to the tank 10, the flow being caused by the difference in pressure existing in the two :tanks; The inlet end of conduit '13 is located in a position to catch the strongest solution in the tank 11 and the outlet end is located at the top of the tank 10 over a baffie plate 16 so that the strong solution enterin this tank is instantly subjected to the re uced pressure, thus immediatel' starting vaporization. The inlet of condult 14 is at the bottom of the. tank 10 and its outlet at the bottom of'tank 11, and throu h this-com 1 'lutionof the refrigerant. Inasmuch as the ,cated at 17 in the drawi -solution assing t .the solution used may be 0 strength. For ordinary purposes it is desirsary, such as a rotary pump, which'is indi- It 'will be understoo that the term 'stro .and weak as a gliedto the atrengt of the solution at 1' erent points in the system, are relative only any desired able to use a comparatively strong solution inasmuch as the refrigerant, as'ammoma,

' will not readil vaporize from a weak solution,-e xcept w on a high vacuum has been created above its surface, which requiresa I While the use of a strong solution may in- 1 ure in the absorber to some large capacity vacuum pump or exhauster'.

crease thep extent, this will not interfere with .theef: fieien'to ration of the machine, the temper .ja'wre Q *the refrigeratog-notflbeing afiected,

rough the conduit 14 is. passing mm a region'of- 'low pressure to a region of higher pressure, a pump is necesinasmuch as ea set and only a slight increase in the amount of power supplied to the pump 17 being necessary a he conduit 13 includes a tank 18 sur-- rounding on all sides a smaller tank 19 which is included in the conduit 14. These tanks are liquid tight so that the liquids ing to the absorbing tank may be quite warm and by means of the arrangement illustrated the heat of the fluid passing through one conduit is largely given off by conduction to the liquid flowing in the opposite direction. This portion of the apparatus is known as the heat exchanger.

A fourth conduit-20 has its inlet in the bottom of the tank 10 and its outlet in the top of this tank, the intermediate ortion being disposed conveniently'in some ice box,

refrigerator, or cold room, ofany description. A pump 21 is included in this circuit and its function is to constantly cause a positive circulation of the cold solution from the vaporizing tank 10 through-the external or work circuit. To aid the absorber to rap- .idly absorb vapors entering through the 'conduiti12, 1t 15 provided with a 'coil 22 through which cooling water is constantly circulated.

' .If the refrigerant consists of a solution of ammonia gas in water, for every pound of ammoma gas withdrawn from the solution in "the tank 10 about 825 B. .T.. U. are

extracted from the solution, and when a pound of ammonia s is absorbed in the solution in the tank 1 the 825 B. T. U. are

liberated and the system therefore eonstantly transfers heat from the work circuit 20 to the absorbing tank 11, from which it is removed partly by radiation and partly by conduction to a stream of cold waterpass in through the coil 22. y

11 some instances the vacuum pum illustratedfin 1 may be dispense with. When the so ution is of suflicient strength anejector may be substituted as shown in Fig.2. The ejector 23 is aided in creating a. vacuum in the tank 10' by the well known tendency of ammonia gas to pass instant] into a solution wheirbroughtin pntathwit water and therebyfglreatly assisting the; aspiratm 'a'ctlon of t e e'ector. This decreases t \erefore the rapi ity of flow and the quantity of the liquid necessarily passing through the ejector for creating the vacuum. Solution drawn from thebottom' of tank 11' isforced by the rotary pump 24 through the ejector and back into the tank,

thereby absorbing and entraining or aspirating the vapors passing, through the pump or conduit 12' and creating a partial vacuum in the tank 10'.

The method described may be utilized efficiently and satisfactorily in plants of large size, but is particularly usefulin small domestic units, inasmuch as heat is not required, and only one or more motor driven pumps required together with a cooling coil by-passed from the house water supply. In addition, the numerous safety devices such as automatic high pressure cut-oflt' switches, and switches responsive to the pressure of cooling water in the coils, together with the complicated and expensive wiring and switchboard's"necessitated thereby, are not required. Failure of the current supply to the motors or of water supply to the absorber will not bring'about a dangerous con- 'dition in the system.

The method of refrigeration described may be varied within the limits indicated by the appended claims.

Having thus described the invention what is claimed as new and. desired to be secured vapor of said volatile fluid from above the surface of the solution and discharging said vapor into an absorber, circulatin part of the cooled solution through a re rigerator and back into the closed vessel, circulating a part of the cooled solution through an exclosed vessel by removing the vapors ofsaid fluid from above the surface of the solution and discharging said vapors into an absorber,

absorbing the vapor removed in a part of the cooled solution, and using another part of the cooled solution for refrigerating purposes.

3. A method of refrigeration consisting in cooling a solution of a volatile fluid in a closed vessel by removing the vapor of said volatile fluid from above the surface of the solution and discharging it into an absorber. absorbing the removed vapor in a part of the cooled solution and returnin it through an exchanger to a closed vesse and using another'part of the cooled solution for re frigerating purposes.

In testimony whereof I affix m si nature.

BURCHARD T 0 NS. 

